The present invention refers to a device for filling and closing disposable bags for containing paper documents, in particular banknotes.
Such device is intended to be used in machines for storing banknotes, usually present in banks, supermarkets, shopping malls or the like.
In the prior art, the banknotes are introduced into these machines through an inlet port and they are then inserted into boxes or into plastic bags removably housed in the machine.
In case of use of plastic bags, they can advantageously be of the disposable type, i.e. bags which, after filling, are sealed by appropriate sealing blades at the edges of the their mouth so that, once opened, they cannot be used again.
Obviously, the use of plastic bags instead of rigid boxes implies various difficulties both as regards fixing the bag to the machine and introducing the banknotes into the bag up to its correct filling, these difficulties essentially being due to lack of rigidity of the bag and in particular to the flexibility of its walls. On the other hand, the disposable plastic bags are simple and inexpensive to be made, they are light and easy to be handled and they do not require any maintenance.
US-A-2011/0052363 discloses a system in which a banknote is introduced one at a time, through a roller feeding device, into the bag, which is placed horizontally and fixed to a support frame provided with a seat within which the bag is initially rolled. Each banknote is introduced into the bag oriented vertically and, as the banknotes are progressively introduced into the bag, the pack that is thus formed is translated horizontally along a conveyor belt which supports it, thus causing an extension of the bag which unrolls from its seat. The pack of banknotes is laterally accompanied by a support plate at the bottom of the bag, while a pressing element on the opposed side of the pack with respect to the aforementioned support contributes to keep the banknotes constantly compact in the bag.
The solution described in this prior art document however implies a considerable structural complexity and, thus, even high production costs.
Document WO-A-02/19289 provides for a piston for facilitating the entry of the banknotes into the box or into a bag.
DE-A-102009053155 discloses a system for filling a bag, with a plate for the lower support of the bag containing the banknotes. The plate is vertically movable downwards as the bag is filled and it is provided with a central passage for the insertion of a “tail” portion of the bag. The machine also comprises a pair of plates, in intermediate position with respect to the height-wise extension of the bag, horizontally movable by acting from outside the bag so as to divide the bag into an upper portion and a lower portion. A piston is vertically movable to firstly compact the banknotes in the upper portion of the bag and then push them, due to the mutual departure movement of the pair of plates, in the lower portion of the bag.
However, this is a complex solution, with many movable parts. In addition, the bag is pressed between the horizontally movable plates and the banknotes stacked in the upper and lower portions, so that the aforementioned horizontal movement of the plates may lead to the risk of breaking the bag.